fix(peek): decode timestamp param properly (#12796)

web/src/components/table/peek/peek-observation-detail.tsx

@@ -11,9 +11,14 @@ export const PeekViewObservationDetail = ({
 }) => {
   const router = useRouter();
   const peekId = router.query.peek as string | undefined;
-  const timestamp = router.query.timestamp
-    ? new Date(router.query.timestamp as string)
+  const timestampParam = router.query.timestamp as string | undefined;
+
+  // Decode the timestamp parameter before parsing as Date
+  // This handles cases where the timestamp might be URL-encoded
+  const timestamp = timestampParam
+    ? new Date(decodeURIComponent(timestampParam))
     : undefined;
+
   const traceId = router.query.traceId as string | undefined;
 
   const trace = usePeekData({